I am reminded of the Israeli apples, Enshimer (?) and Anna.

The Israeli apple cultivars, like Ein Shemer (sic) and their descendants, still
require something of a dormant period. I have never heard of any apples that
grow in a tropical area, like southern Florida. The achievement of Ein Shemer
is that it requires fewer chilling hours during the winter in order to bloom
and set fruit. It was developed for northern Israel, & is very successful in
our southern states.
The following explanation refers to peach trees, but the principle is the same
for apples & other hardy fruit trees.
Peach trees are deciduous and drop their leaves in the Fall and go into a
developmental state known as dormancy. As the winter progresses the trees go
into another state known as rest, during which they cannot grow even if
environmental conditions are favorable for tree growth. Exposure to chilling
temperatures is necessary to overcome this period of rest, after which normal
bud break and growth can begin once growing conditions are favorable. The
minimal necessary duration of chilling length for any particular variety is
known as the chilling requirement for that variety. Temperatures effective in
satisfying the chilling requirement normally range from 32 F to 50 F, with the
optimal temperature being approximately 45 F.

Do you think that perhaps these warm climate elms have adapted and no
longer require the dormant period?

I would like to know if temperate trees in southern California are capable of
blooming & fruiting. It is not an issue with elms & sweetgum, but what about
bonsai crabapple?

Iris,
Central NY, Zone 5a, Sunset Zone 40
"When you come to a fork in the road, take it." Yogi Berra